Global warming may spur increased growth in Pacific Northwest forests

From an Oregon State University press release

https://i2.wp.com/www.nasa.gov/centers/goddard/images/content/156030main_Conifers_JPG.jpg

Northwest conifer forest. Source: NASA

CORVALLIS, Ore. – Global warming in the next century could cause a significant increase in the productivity of high-elevation forests of the Pacific Northwest, a new study suggests. However, forests at lower elevations – which in recent years have accounted for more than 80 percent of the region’s timber harvest – could face a decline in growth.

The potential changes, which are based on the projections of computer models, would be most pronounced in Washington. In that state, high-elevation forests could see their productivity increase substantially, from 35 percent a year to as much as 500 percent, depending on which climate scenario is used.

In Oregon, similar elevations might see more modest forest growth increases of 9 to 75 percent.

Overall, forest productivity could increase about 7 percent annually in forests west of the Cascade Range and 20 percent in forests east of them, in conclusions based on one climate scenario that largely reflects current trends of energy use, globalization and economic growth. However, management practices, genetic limitations, and changes in natural disturbances such as disease, insects and fire were not included in the study, and can also affect productivity.

These findings analyzed changes in forest productivity further into the future than most previous work, and were just published in Forest Ecology and Management, a professional journal, by researchers from the College of Forestry at Oregon State University and the Pacific Northwest Research Station.

“There’s a lot of variability here, depending on which climate scenario turns out to be most accurate and what policy changes are made as a result,” said Darius Adams, a professor of forest economics at OSU. “And there are dramatic differences in forest regions and elevations. Clearly the forest growth is likely to increase the most at higher elevations, but it’s worth noting that those forests never had very high growth rates to start with.”

According to Greg Latta, an OSU faculty research assistant and principal investigator on the study, most of the climate scenarios that were used showed increases in temperatures – from one to eight degrees – but precipitation projections were all over the map, sometimes up and sometimes down. At lower elevations, tree growth is constrained when moisture is limited and drought stress is an issue.

“The lower-elevation forests are getting warmer just like those at higher elevations, but in most scenarios the precipitation doesn’t increase enough there to offset that,” Latta said. “The cumulative effect could be declines in forest growth of 1 to 3 percent a year in low-elevation Oregon forests, which could have a substantial long-term impact if trees are being managed for timber harvest.”

Among the findings of the study:

  • Any climate scenario that shows an increase in future temperatures could potentially lead to an overall increase in forest productivity in the Pacific Northwest, especially in Washington.
  • Increases in high-elevation forest productivity were partially offset by probable declines in lower-elevation forest productivity.
  • Private timber lands that have accounted for 83 percent of the timber harvest in this region over the past decade are concentrated at lower elevations.
  • The models showed that increases in forest growth at higher elevations could increase carbon sequestration for those areas, but they did not include potential changes in fire frequency and severity, which are also affected by biomass accumulation.
  • Other possible changes not reflected in the productivity projections were disturbance regimes such as diseases and insect outbreaks that are also affected by climate.
  • The combination of tree mortality and declining future growth on private timberlands could lead to concerns about lower harvest levels and reduced carbon sequestration in the future.
  • Responses to these projected future changes may depend largely on who owns the land, since private and public landowners often have different management objectives.

Forest productivity is important to consider for a range of issues, the researchers noted in their study, including potential timber harvest, habitat for wildlife, fuels that increase fire risk, carbon sequestration and other issues.

The study is also now being extended into Alaska, the researchers said.

“Water availability turned out to be an important factor for much of Oregon and Washington,” said Tara Barrett, a co-author and research scientist with the U.S. Forest Service. “We’re extending the project to coastal Alaska, where length of growing season is likely to be a more important factor than water availability, so it will be interesting to see if results are similar for that region.”

Forests and their potential growth may also play a significant role in future mitigation efforts to reduce greenhouse warming and the use of “carbon credits,” experts say.

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26 thoughts on “Global warming may spur increased growth in Pacific Northwest forests

  1. If I assumed that the moon was going to have an atmosphere, I could write a wonderful study on how lush the forests there will be.

    There is one useful piece of info: “However, forests at lower elevations – which in recent years have accounted for more than 80 percent of the region’s timber harvest – could face a decline in growth.”

    So we know that forests at lower elevations, accounting for 80% of the region’s timber harvest, are going to do quite well in the near future.

  2. So if the globe warms, nature will respond biologically, as it did when the Earth was really warm millions of years ago.
    If the globe warms.

  3. And global cooling may restore the kilometer of ice that once filled Puget Sound. Sad and lame and sad.

  4. Here is another story of three growth driven by cosmic rays!
    It makes more sense than any speculation on three growth in the next century.
    We can even predict the weather over a time frame from more than 1 week so how the hell can we predict how our climate will looks like in 100 years from now?

    As Moncton stated in his excellent speech, there is no computer model that is able to make any future climate prediction.
    Any study that claims it can is not worth the paper it’s printed on.

    http://motls.blogspot.com/2009/10/cosmic-rays-probably-drive-tree-growth.html

  5. “Forests and their potential growth may also play a significant role in future mitigation efforts to reduce greenhouse warming and the use of “carbon credits,” experts say”.

    I D I O T S

  6. So Scottish trees do not follow the Briffa Law of Tree Rings. But then again the Scots have always been a contrary people. I know, I’m half Scots

  7. Will CO2 reduction seem criminal if the climate cools significantly? Will the comfortable elites continue to insist that global warming MUST occur even while people freeze? Interesting times.

    CO2 is a gas too far, IMO.

  8. Ron de Haan (16:19:00) : “We can even predict the weather over a time frame from more than 1 week so how the hell can we predict how our climate will looks like in 100 years from now?”

    This argument always bothers me. I can’t predict whether you’ll win or lose in your first hour at the casino, but, on the average, I can probably come pretty close to guessing how much you’ll have when you leave a week later. Inability to predict short-run behaviour doesn’t preclude prediction of long-run results.

    Of course, the Earth isn’t a casino, and if it were, certain “scientists” would be banned for life. We just don’t know enough about it to predict much of anything. Everything I’ve read makes me think it’s an incubator with redundant controls.

  9. Mr.artday is perceptive. The vast evergreen forests of the PNW have been a transitory phenomenon during the last 2.5 million years, repeatedly extirpated and replaced by ice and tundra for 90% of that epoch.

    The current forest invaded about 11,500 years ago from coastal refugia to the south. Some species present today (western red cedar, for example) do not show in the paleo-pollen record until 6,000 to 9,000 years ago, which is interesting because humanity showed up at least 12,500 years ago. Resident people preceded the Holocene forests of the PNW.

    Forest productivity has not been constant or fixed during the Holocene, but instead has varied as cool/dry, warm/wet, and other weather patterns (such as the PDO) have risen and fallen. The modelers could have done a better job if they had used longitudinal historic data rather than imposing climate change scenarios on existing forest growth models (based on recent growth data).

    The authors do acknowledge, however, that their projections are of gross growth, not net growth, which includes mortality. They acknowledge that they cannot predict mortality with any degree of certainty, and so do not even attempt it.

    The entire exercise is completely speculative from many perspectives. Models based on models are twice removed from reality. And there have been no regional growth changes over the last 100 years that can be attributed to climate change, although the claim is made that a 2 degree rise has occurred during that time. The trees have not responded, or else the response is so tiny that it cannot be detected or separated from other growth influences.

  10. “but precipitation projections were all over the map, sometimes up and sometimes down.”

    “however, management practices, genetic limitations, and changes in natural disturbances such as disease, insects and fire were not included in the study”


    Competent managers will not be influenced by this (computer fantasy) “research”. (Note the word “competent” in my statement.)

    The lack of understanding of the hydrologic cycle is not something that can be swept under a rug.

    …nonetheless, people will continue with the computer fantasy theme that pulls in grant money (at present) – and people justify all the charades with the need to provide for their families (…at the expense of other peoples’ families – so not ok).

  11. “Of course, the Earth isn’t a casino, and if it were, certain “scientists” would be banned for life.”

    I assume you are referring to the spot counters:

    “ten minutes to Maunder… ten minutes to Maunder… “

  12. It is the ‘experts say’ bit at the end I like.

    Of course there are always these unamed, unquoted experts around. Where do you think reporters keep them? In a convenient cupboard perhaps?

    Kindest Regards

  13. I guess this means I’m going to have to have the Red Wood in the backyard trimmed/windsailed again.

  14. Anyone know where I can buy a couple of hundred acres of high mountain forest? Think of the offsets you’d have.

  15. “Of course, the Earth isn’t a casino.”

    Absolutely, so why make the comparison in the first place?

    A casino knows how much profit it will make in the long run because it has a positive expectancy of a couple of percent. However, the climate is not the result of a series of random outcomes like a roulette wheel, but of physical interactions of such complexity that we have only the crudest understanding of how they work.

  16. I don’t need no fancy climate model to tell me that global warming would increase high elevation forest productivity. Anyone with a bit of common sense and a basic understanding of biology would come to the same conclusion.

    The common sense approach wouldn’t quantify the increase, but then again, saying that productivity will increase “from 35 percent a year to as much as 500 percent” and saying that “productivity will increase” basically amounts to the same thing. One just uses more words.

  17. “The potential changes, which are based on the projections of computer models, would be most…ZZZZzzzzz zzZZzzz…”

    Sorry, I am automatically tuning out anything and everything that’s a prediction of future events based on computerized Ouija boards.

  18. “Global warming in the next century…..from one to eight degrees”. As usual, the assumption is always rising temperatures; and, as usual, no mention of historic
    temperatures. So, I took a trip to the State of Washington via USHCN to look at the records. In general, mean temperatures over the past century showed an increasing trend after 1950 to the previous highs of 1940 – 1950 or some higher
    but with recent declines. Of greater significance, most all MAXIMUMS decreased over the entire period. It was only the minimums which increased. Otherwise, there is no correlation of temperature rise with CO2 concentration as is the usual assumption. In conclusion (as BernardP has stated), “there is no global warming” to justify the basis of this study.

  19. Recurring to models is necessary where there are not known natural laws. This shows we are lacking a real cosmology. This is why science, particularly “official” (or I would rather say: “progressive”) occidental science is groping in the dark.

  20. If I had a piece of bread I could make a ham sandwich if I had a piece of ham.

    Must be great to be paid for sheer speculation.

  21. Sam (08:41:10) :

    Most all MAXIMUMS decreased over the entire period. It was only the minimums which increased.

    Ever heard of storage radiators, they were made of bricks and heated up during the day, couldn`t be the UHI effect could it.

  22. As I understand modeling, when you assume (speculate) that the premises and conclusion of a hypothesis are correct and then design a model based upon those assumptions, the model will produce scenarios that do so. Some how this does not appear to be scientific research. Under scientific method, should not the model be programmed to test and refute the hypothesis?

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